* {
	margin: 0;
	padding: 0;
	list-style: none;
	text-decoration: none;
	box-sizing: border-box;
}

.box {
	margin: 100px auto;
	width: 500px;
}

.nav {
	overflow: hidden;
}

.nav li {
	float: left;
	width: 100px;
	text-align: center;
	padding-top: 20px;
	padding-bottom: 20px;
}

.nav li a {
	color: #3C3C3C;
}

.main {
	overflow: hidden;
}

.main>ul>li.active {
	display: block;
}

.main>ul>li {
	display: none;
}

.main ul li a {
	display: inline-block;
	width: 50%;
	float: left;
	text-align: center;
	color: #666;
	margin-bottom: 10px;
}
